NJU7347 -1- single-phase dc brushless motor driver ic general description the NJU7347 is single-phase dc brushless motor driver ic. it features mos-fet driver circuit for better output characteristics. it features lock detect, frequency generator output and thermal shutdown circuit. maximum output current is 200ma(12v). input offset voltage is 7mv. it is suitable for 12v high current small fan-motor applications. package outline NJU7347r features ? operating voltage 3.5 to 14v ? frequency generator output ? thermal shutdown circuit ? lock detect / auto release circuit ? fg output ? low operating current ? low saturation output voltage ? vsat= 0.3v @io= 200ma ? cmos technology ? package outline vsp10 block diaglam pin function 1: ct 2: fg 3: v ss 4: out b 5: v dd 6: v dd 7: out a 8: v ss 9: in- 10: in+ (note) all v dd and vss pins should be connected th e power supply and the ground respectively. otherwise, the electrical characteristic may no t satisfy specifications ld 7 8 9 10 6 4 5 3 2 1 tsd
NJU7347 - 2 - absolute maximum ratings (ta=25 c) parameter ratings symbol (unit) note supply voltage 15.0 v dd (v) input voltage -0.3 v dd +0.3 v id (v) output current (continuance) 200 i o (ma) output current (peak) 600 i o peak (ma) operating temperature range -40 +85 topr ( c) storage temperature range -50 +150 tstg ( c) power dissipation 400 p d (mw) device itself recommended operating conditions (v dd =12v, ta=25c) parameter symbol condition min. typ. max. unit supply voltage v dd - 3.5 - 14.0 v output current i o - - - 200 ma
preliminary NJU7347 - 3 - electrical characteristics (v dd =12v, ta=25c) parameter symbol condition min. typ. max. unit general operating current i dd - - 3.0 5.0 ma thermal shutdown temperature t tsd - - 180 - c thermal shutdown hysteresis t hys - - 50 - c hall amplifier input offset voltage v io - -18 - 18 mv feedback resistance r f - - 37.5 - k ? input common mode voltage range v icm - 0.2 10.5 - - v output v oh io=+200ma 11.55 11.70 - maximum output voltage range v ol io=-200ma - 0.30 0.45 v r onh io=+200ma - 1.5 - output resistance r onl io=-200ma - 1.5 - ? fg l output voltage v fg i fg =5ma - - 0.6 v fg h leak current i fg-leak v fg =12v - - 1.0 a lock detect circuit* lock protect operation voltage v lop - 4.0 - - v lock detect charge current i chg - - 3.2 - a lock detect discharge current i dchg - - 0.32 - a charge / discharge ratio i chg / i dchg - - 10 - clamp voltage v cl - - 2.3 - v detect voltage v id - - 0.6 - v
NJU7347 - 4 - truth table power dissipation 400 25 50 75 100 125 150 a mbient temperature [d c] 50 250 350 200 power dissipation [mw] 0 100 150 300 85 in+ in- c t out a outb fg h l l h l h l h l l h l h l h h z l l h h z h l in p u t out p u t
preliminary NJU7347 - 5 - typical characteristics vdd-idd in+=v dd, in- =v dd 0 1 2 3 4 5 024681012141618 vdd[v] idd[ma] vfg-ifg vdd=12v 0 0.2 0.4 0.6 0.8 1 02468 ifg[ma ] vfg[v] vdd-voh io=200ma 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 v dd[v ] voh[v] vdd-vol io=200ma 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 vdd[v] vol[v] io voh v dd=12v 10.6 10.8 11 11.2 11.4 11.6 11.8 12 0 200 400 600 io[ ma ] voh[v] vol idd vdd=12v 0 0.2 0.4 0.6 0.8 1 1.2 1.4 0 200 400 600 idd[ma] vol[v]
NJU7347 - 6 - application note the NJU7347 is a single-phase dc brushless motor driver ic in small vsp10 package. with minimal external components, it can drive up to 200ma of motor current for small fan application. [application circuit example] in+ in- v dd ld v ss outb out a fg motor hall element c2 r1 r3 r2 fg out NJU7347 v dd gnd c1 d1 [design notes] above application example is designed for 12v operation with motor current of 200ma. it uses the following components: hall elements: hw101a (ake) 1. selection of c1 and d1 : c1 is used for a noise reduction purpose. a typical value is 0.1uf. optimize the value in actual operating conditions if necessary. d1 is a diode for protection against reverse voltage supply. silicon rectifier diode (wo3c, 10d1 and equivalent) is appropriate. 2. lock protection function (design of c2 value): lock protection function, consists of motor lock detection and auto resume function, is a safety feature to protect a motor and a driver circuit from fatal destruction in case of motor halt. motor lock detection detects motor halt due to irregular load conditions and then cuts motor driving current f or safety operation. a value of c2 determines lock detection time (t on ) and auto resume time (toff). lock detection time (ton) is given by: [] sec 2 chg id cl on i v v c t ? =
preliminary NJU7347 -7- where c2 is 0.47uf: auto resume time (toff) is given by: where c2 is 0.47uf: in actual application, lock detection time (ton) is affected by the mechanical time constant of a motor. therefore, constant start up must be confirmed in actual evaluation taking operating variations (i.e.temperature, voltage change and so on) in consideration. a typical value of c2 is either 0.47uf or 1uf depending on a motor. 3. design of hall element bias resistance ( r1 and r2 ) hall amplifier is a differential amplifier. the common-mode input voltage is between 0.2v and v dd -4v and the input signal must be within the range. non-excitation hall bias voltage is to be set at a half of v dd for effective use of common-mode input voltage range. therefore the same value of hall bias resistors is selected for r1 and r2. given that the bias current is set to be 5ma by hw101a datasheet, r1 and r2 can be determined as follows: ? = = ? = = = + + ? k r r k ihbias v rin r r dd 1 2 1 4 . 2 10 5 12 2 1 3 ? [ ] sec .25 0 10 2 . 3 6 . 0 3 . 2 10 47 . 0 6 6 = = ? ? o n t [] sec 2 dchg id cl off i v v c t ? = 10 .32 0 [ ] sec 2 0 6 . 2 10 47 0 6 6 = ? = ? ? of f t .5 .6 to n in+ in- outa outb ct fg lock ld release vid vcl toff toff lock protection operating time
NJU7347 - 8 - the output voltage of hall elements is influenced by the bias current and magnetic flux density of hall elements. the optimum input voltage of NJU7347 is 100mvp-p and higher. with such input voltage, the highest efficiency can be obtained. 4. design of fg output resistsnce ( r3 ) fg out(fg:pin2) is a open drain output and r3 is a pull up register. a typical value of r3 is 10k ? . the timing chart of fg out is as follows. note that the pull up resistance shall be connected to below supply voltage. the specifications on this data book are only given fo r information, without any guarantee as regards eithe r mistakes or omissions. the application circuit in this dat a book are described only to show representative usages o f the product and not intended for the guarantee o r permission of any right including the industrial rights. hall input in+ fg terminal voltage the specifications on this data book are only given fo r information, without any guarantee as regards either mistakes o r omissions. the application circuit in this data book are describe d only to show representative usages of the product and no t intended for the guarantee or permission of any right includin g the industrial rights.
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